There are quite a few systems of building that are based on special
manufactured products. These systems could be considered "alternative"
since they do not represent typical, mainstream building techniques.
While greenhomebuilding.com is mostly interested
in promoting ways of building that utilize natural materials that require
little industrial processing and transportation, it is recognized that
not everybody wants a house that is made of dirt, straw, field stones,
curved tree parts, etc.

It is a fact that many of the manufactured systems, once the house
has been created, provide an excellent, durable, energy-efficient domicile.
Even though the house may be constructed of considerable steel, cement,
synthetic insulation, or other materials that are high in "embodied
energy," over the lifetime of the house the energy saved in comparison
to more conventional construction may be considerable. For this reason,
I have included this page devoted to a variety of these manufactured
systems. I am not promoting any particular one, nor do I receive
any money from any of these manufacturers for including them here. I
believe in being fully informed about all possible ways of building.

This material was first brought to my attention by a local builder who has become a distributor for it and is building with it locally. It is really pretty fascinating stuff, with some great characteristics. In a way it is like man-made pumice, in that it is masonry, but is still rather lightweight. It is highly insulating and completely fireproof. I once held a one-inch thick piece of it it in my hand while a blow torch heated the opposite side, and I could barely feel it get warm! It can be cut with any carbide-tipped tool into very precise shapes, then the blocks can be "glued" together with ordinary masonry tile products. Precut blocks are available that have channels in them for standard rebar bond beam applications.This material has been used for buildings in Europe for a couple of decades, but is just now being tried in the United States. It is fairly expensive, but I would expect it to be extremely durable and create well-insulated and attractive structures. Interior and exterior finishes can be spayed on to provide a uniform, durable and colored surface. It has occurred to me that this stuff could be precut into "kit houses" that were architecturally intricate and beautiful, and would just need to be assembled by numbers.

The Wonders of AerBlock is an article written by Kelly Hart about AAC and how Michael Baron discovered and promotes its use.

Here are some links related to this material, sometimes called AAC:sider-oxydro.com makes AAC. taunton.com article about building with AACaerblock.com the local distributor who showed me the stuff.

Inca Blocks

www.incablock.com describes a unique hollow concrete block system that is interlocking and requires no mortar, so it is very fast to assemble.

Domespace

Domespace is what this French company calls their unique, rotating domes that can turn to face the sun as it traverses the sky. These domes have been built in many countries. Although they can be very energy efficient, I wouldn't exactly call them "ecological", since they are made almost entirely of wood and are based on a fairly high-tech concept. You can find out more about them by going to their website: www.domespace.com .

Earth Block

woodbrik an article about a product made from recycled wood fiber and fly ash.

gardendome.com is a site that is great for becoming educated about the many forms that geodesics can take. As well as offering kits for building these, they offer free patterns online that you can use to print and cutout paper models.

world-science.netThis article discribes a unique approach to creating housing by spraying a ceramic-like material on a stryrofoam or other naturally woven frame material to create a solid structure. grancrete.net is the website of the company itself. gigacrete.com describes a cementious panelized product that utilizes various waste materials to manufactrure. More information about Grancrete is available here: www.rexresearch.com.

Here is a very informative article about Magnesium Oxide which is used as a cement in these products, comparing it to Portland cement and pointing out its many benefits.

Ceramicrete is formed by mixing magnesium oxide powder and soluble phosphate powder (common, low-cost materials) with water. The process is very similar to that for making concrete, using commercially available equipment that mixes the powder components into the binder. The wet material (binder, aggregates, and water mixture) can then be pumped, gunned, or sprayed, also with commercially available equipment. The resulting material is nonporous, with compressive strength higher than that of concrete.

An all-natural magnesium oxide cold ceramic cement based building panel that can replace drywall, OSB and plywood. See www.geoswan.com for more information.

Here is a very informative article about Magnesium Oxide which is used as a cement in this product, comparing it to Portland cement and pointing out its many benefits.

Liteblock Aerated Concrete

LiteblokT is an aerated, precision molded concrete block. Unlike autoclaved aerated concrete, it is not autoclaved. Rather, a non-toxic foaming agent is introduced to create a closed structure of discrete air pockets. The blocks are laid without mortar and are interlocking and lightweight allowing for significant savings in construction time and cost. Applications include residential and commercial construction, fences and retaining walls.

They give a "thermal conductance" value of 0.759 BTU-in/hr-ft 2-° F, which translates to about R-1.4/in., so the 5" thick block would be about R-7, but this can be misleading, since the overall performance of the wall system may measure much better than this. Using the IECC mass adjusted tables you get an R-18 equivalent in Houston, Texas, where the manufacturing plant is. You can learn more about this product by visiting crescoconcrete.com.

Inflatable Canvas/Concrete Shelter

This article describes a unique concept for creating almost instantaneous shelters with cement-impregnated inflatable canvas: wired.com/news

ThermoPlan / Ziegel Blocks

Thermoplan or Zeigel Blocks are fired clay blocks which use about 1/3 less energy to make compared to concrete blocks, and about 2/3 less CO2. They are fast, simple and ideal for a self builder to use. About 50% of German homes are made this way and the technology is spreading to other areas of Europe.

Thermoplan systems use Ziegel blocks with a thin bed of mortar, to provide a breathing wall construction system. When combined with woodfibre board they can form a thermally and acoustically high performance shell. The Ziegel blocks come as part of a full load-bearing external and internal wall masonry system, and combine high thermal performance with robustness, speed of build and a breathing wall design.

Because of all the trapped air and the thickness of the walls, these blocks provide reasonable insulation, while at the same time do provide some degree of interior thermal mass for maintaining constant interior temperatures. This is an unusual combination of these two factors in a single wall system.

Wood Wool Cement Board

Wood wool cement board is versatile building material made from wood wool (excelsior, or wood slivers) and cement. The world wide acceptance of WWCB proves its versatility in applications and its durability in any climatic condition. The main characteristics are: fire resistance; wet and dry rot resistance; freeze-thaw resistance; termite and vermin resistance; thermal insulation, providing energy savings; acoustic performance - sound absorption; acceptance of a wide range of finishes.

Wood-fibre boards are rigid insulation boards made from wood chippings and are available in Europe. They are manufactured from the by-products of sawmills. Softwood chippings are pulped and mixed with water and mechanically pressed into boards, typically 20mm thick. Typically a binder of natural tree resin is used. Various boards are available for different applications: insulating sarking board for roof constructions; below-screed flooring board for both thermal and acoustic insulation; internal and external insulating lining boards.

Volumetric, Continuous Mixing of Concrete, and other Materials, on Site

by Simon Stanfield

Kelly Hart asked me to write a paragraph or two on the subject of making cementitious building materials right at project sites. The benefits of doing this, especially using special or native materials, are so enormous, I really don't know where to begin, but here goes
It is often impossible to use a ready mixed concrete service for special projects. Travel time can be a problem because of the life span of plastic (wet) concrete. Not all ready mix companies will batch the materials desired because of the cost of doing so, and the risk of contaminating their equipment for regular deliveries. Also, the cost of doing business with a conventional ready mix company may be prohibitive. If they don't have the stuff you want to mix in their batch bins, how will they accurately proportion and load it? Then there is the perpetual problem of getting a 60,000+ pound load into the vicinity of your project.

Truck Mounted Unit on the Job With Placing Pump

A volumetric or continuous mix unit on site can resolve this dilemma. These are self-contained concrete production systems mounted on a skid or truck chassis. Some larger capacity units have their own power and are mounted on fifth wheel semi-trailers. In this case, a truck can simply drop the trailer in place, unhook and then ideally hook up a dump trailer to haul in materials. Cement can be supplied in all cases with a portable bulk cement tank, super bags or even paper bags. Water is often available at the jobsite from a well, stream or pond, but should be potable to avoid a lot of undesirable organic matter permeating tanks, pumps, valves, gauges and the mix itself. Depending on the materials being blended (the mixer part of these systems resembles nothing so much as a kitchen blender), most can be trucked in and loaded with a skid steer or front-end loader.A volumetric (thus named because it proportions by volume rather than weight) concrete plant occupies a footprint the size of a truck parking space. An area on each side is necessary to access the holding bins with a loading device. Power can be an integrated diesel engine, truck engine or electric motor. The system is powered hydraulically, so it's simply a matter of powering the hydraulic pump. These things will blend anything. I have personally set up machines to homogenize shredded wood, light weight aggregate, heavy weight aggregate, Styrofoam beads, just sand, just stone, polymers, fiberglass, foam, dirt, shale and a hundred other things. Constructing on site with native materials is a grossly underutilized application of this equipment. (Much of Interstate 80, "Mainstreet USA," was built this way with materials excavated from the environment beside the road grade. Communities have capitalized on this by establishing parks and wildlife sanctuaries in the resulting wetlands.)ASTM Specification C-685 governs the manufacture and usage of volumetric equipment. It must conform to certain standards and be able to proportion materials with less than 1% direct variation. This is less variation than most weight-batch systems exhibit. Usually a belt or chain drag system pulls the materials being blended through calibrated strike-off gates. Special materials can be added as liquids through flow meters, or very low dose vane feeders as powdered solids. Foam can be injected at the mixer throat from a foam generator. Reinforcing fiber can be added at the most advantageous point. Cement, or the binder, is added with water and admixtures where all materials are gathered into a fully enclosed auger-style mixer. This is interrupted auger flighting in a high-shear, high-speed configuration. The auger and shear blades are faced to prevent premature wear and combine the best aspects of all types of mixing - shear, tumble, pressure and counter-current. The augers will mix anything homogeneously. However, if the materials are totally incompatible, the end result may not be the best. "Tuning" the proportions is very important.I think that this method of producing building materials on site is by far the best. It enables the contractor/engineer to have the designed mix virtually on tap. You don't have to mix a batch. Just pull a lever and produce as much as you like. The unused portions reside in the holding bins separate from each other until needed. Mix designs (recipes) can be changed at will. A simple readjustment of the strike-off gates and regulating valves will alter proportions of the materials in the machine immediately. If a change of components is required, just load in the new stuff.If ultimate strength is a consideration, then the mix being produced will most likely be a type of concrete. The most important factor in determining cured strengths of concrete in addition to the cement content is the water/cement ratio (weight of water divided by weight of cement). The lower this is, the better the strength will be, provided there was enough water initially to fully hydrate the cement and aggregates. Typically, a volumetric machine will produce a friendly mix in fifteen seconds mixing time with a W/C ratio of .35. Try to get that out of any kind of batch mixer and use it - on site or ready mix.I feel so strongly about this method of making cementitious building materials that I would like to answer questions and/or become involved in any projects where my expertise might be helpful. I have been involved in concrete for over thirty years and travel the country as a Volumetric Consultant.

transmaterial.net features descriptions of newly developed ecological materials, some of which might be used for construction.

construction.com links to an article about making concrete more environmentally sound.

romanconcrete.com links to an article about "Roman concrete" and its similarity to concrete with fly ash.

nova-eplus-home.com features home designes that employ a host of manufactured systems that add up to a very efficient house.

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Of Liability And WarrantyI specifically disclaim any warranty, either expressed or implied,
concerning the information on these pages. Neither I nor any of the
advisor/consultants associated with this site will have liability
for loss, damage, or injury, resulting from the use of any information
found on this, or any other page at this site. Kelly Hart, Hartworks,
Inc.

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